Volatile composition of traditional and industrial Orujo spirits

In this study, fourteen samples of Galician Orujo spirit (seven from industrial and seven from homemade sources) were analysed by gas chromatography in order to determine their content in major volatile compounds, methanol, higher alcohols, aldehydes and esters. The main objective of this study was the establishment of the differences existing in the volatile composition of both groups of spirits, to identify the compounds whose presence is due, fundamentally, to the production process, either with reference to the raw material itself or to the latter distillation phase. The variance analysis of the results obtained indicates that, for most of the compounds, there are no significant differences (p<0.05) in concentration in either of the groups of spirits. However, those compounds whose formation is related with the processing and storage of the raw material show a higher concentration in the spirits from industrial origin. Among these compounds can be cited methanol, 1-hexanol, 1-propanol, ethyl lactate and ethyl acetate whose sensorial contributions are considered negative. On the other hand, 2-phenylethanol (an important aromatic compound that contributes a nuance of roses) shows a higher concentration in the homemade spirits, possibly because of an increased contribution of the tails fraction to the spirit, backed up by the lower average concentration of ethanol in these distillates.